The Plasticity of Memory

I recently read an article entitled, "The Forgetting Pill Erases Painful Memories Forever". The article covered some fascinating concepts that are being investigated in memory. A few of the main points that it covers include:

• Memories are retained by physical connections, or wiring, between neurons in the brain. "For a memory to exist, these scattered cells must become more sensitive to the activity of the others, so that if one cell fires, the rest of the circuit lights up as well." These connections require gene activation and protein synthesis which can include creating new receptors, alter existing receptors and increasing the amount of neurotransmitters.
• Memories consist of two main components, emotion and the actual physical occurrence. Often times extremely traumatic experiences which caused negative emotions such as anger, fear, sorrow or anxiety can be reactivate these emotions when the memory is revisited. 
• Memories are getting rewritten constantly.  Memories are retained by connections patterns between neurons and neurons are made of proteins. Proteins are constantly breaking down and being rebuilt in our body and every time a memory is activated it gets rewritten according to the current emotional state and present knowledge of that person. This concept has been used to treat PTSD (Post Traumatic Stress Disorder) patients by having them revisit the memory while on mood enhancing drugs which has been effective. 
• Memories may be able to be erased someday. Activation of a memory causes the reorganization or re-synthesis of proteins which rewrite that memory. If protein synthesis was blocked temporarily in that cluster of cells were the memory was retained then when the memory was activated the protein structure that would normally be rebuild to retain that memory would no be rebuilt and the memory would not longer exist. This idea is currently only a hypothesis that has been shown to work on rats. When injecting a protein synthesis inhibiting drug into the brains of rats it was shown that the rats no longer remembered that loud music was related to an electrical shock, something that they had know prior to the injection. 

With memories being constantly rewritten every time they are revisited can they be trusted? If we really can erase memories someday what memories, if any would you erase? Science is cool.